Fluid buffer



March 9,1926. 1,576,300

G. BOOTH FLUID BUFFER Filed Nov. 16. 1922 2 Sheets-Sheet 1 1 660/9622? fifiwm Y dwznmza @WM March 9,1926. 1,576,300 G. BVOOTH FLUID BUFFER Filed Nov. 16, 1922 2 s is t 2' Patented Mar. 9, 1926.

UNI-TED .srarag GEORGE" BOOTH, or CHICAGO, rumors, Assren'on r'o MIEHLE Pnrnrme races 82 MFG. Co., or CHICAGO, rrmnorsn Conronnrron or ILLINOIS.

Fnnrn BUFFER}.

Applicati'on filed November 1c; 1922. Serial No.- 601,421.

To all whom,- z't may concern:

Be it known that I, Gnonen Rooms, a citizen of the United States, residing at Ghicago, in the county of Cook and State of Illinois have invented certain new and useful Improvements in Fluid Buffers, of which the following is a specification;

This invention relates to a new and improved fluid buffer and more particularly to an. air cushioninghu'ffer especially adapted for use in connection with the reciprocating beds of printing presses. Certain types of printing presses are designed with: beds which reciprocate moving relative to a cylinder, the latter being adapted to rotate with its surface inengagement withv the bed. An impression is made upon each reciprocation of the bed and in order to operate the press at ahigh rate of production, it is necessary that the bed reciprocate to a relatively high speed which: may reach sixty reversals of movement per minute or greater.

The bed and its: accompanying parts are of: considerable weight and reversal of its movement while operating. at high speed occasions shocks to the mechanism. It is customary, therefore, to provide shock absorbing;means ad'apted to cushion the movement of the bed. A customary means for cuslnoningincludesa cylinder anda piston working therein, the cushioning being accomplished. by compression of air in the cylinder; It is essential for eiiicient cushioning that the cushioning effect be progressive and not be so suddenly applied as in itself to causea shock to the mechanism. In order to insure this progressive application, valve controlled ports are commonly provided: either in the cylinder or piston to control the flow of air from the cylinder, and consequently to control the air pre surein. the cylinder. It is important also that no undue drag be imposed upon the start of the reversing movement of the press and. consequently the valve must be quick in opening to' prevent the formation of a partial vacuum i-n the cylinder.

In-"certaintypes of valves heretofore used in: this connection, springs have been used to control the valve operation. This method of control is objectionable since the springs require rather'delicate adjustment and further do not maintain this adjustment due to fatigue: and crystallization of themetali It is an object of the present invention to 7 provide a new, and improved buffer provided: with swinging valve means adapted to control the flow of air to and fronr the compression cylinder.

It is a further object to provide valve means normally maintained open by force of gravity and further to provide means for adjusting. and: controlling. the opening. y 7

It is an additional object to provide a valve which may be readily modified" to adapt it to differing conditions of speed and recpiiredair pressure.

it is alsoan object to: provide a piston for use in: such structures, the piston comprising. simple and readily adjusted means for l'naintaining. substantially fluid tight engagement with the cylinder walls.-

The piston comprises the head 8 which is threaded upon the end of'the piston rod 9 and locked in: place thereonby thejamv nut 10. As shown in Figure 5; this; piston; is fitted into the cylinder 11, the cylinder be ing provided with the removable cylinder head 12 secured in place by bolts 13. Y

The upper portion of the piston head is provided with: a plurality of ports- 145: extending axially throughthe head. A raised valve face 15' surrounds the ports upon the inner face of the piston head as shown in Figures: 1 and A pair of spaced pivots 16 is secured to the inner face of the'piston head by bolts 17. The valve member 1 8 is provided with the arms I9 engaging the pivots 16. The inner-face of the-upper portion of the valvemember 18 is provicledwith the contact members 20 adapted to engage the raised valve face 15. These members 19 may be made of leather or other suitable material.

Thelower portion 21 of the valve member 18 is bent at an angle upon a transverse line and makes an angle of approximately 30 degrees with the upper portion. The adjusting bolt 22 is threaded into the piston head and the head of the bolt engages the lower portion 21 of the valve member to limit its inward swing. The washer 23 is shown under the head of the bolt 22 and the bolt is adjustable for the addition or removal of similar washers.

The piston head is provided with the cir cumferential shoulder 24 adapted to receive the packing ring 25 and to engage the shoulder 26 of the packing ring. This ring 25 may be formed of fibre or metal or other suitable material. The flexible packing ring 27 is secured to the piston head by the clamping ring 28 and bolts 29. The packing ring 27 engages the cup-shaped face 39 of the packing ring 25.

Gravity acting upon the valve closure normally maintains it inthe position in which it is shown in the drawing, in which position the valve closure is outof engagement with the valve face. The distance between the closure and valve face and consequently the movement necessary for closing may be varied by adjusting the screw 22 and adding or removing washers or shims under the head of the screw.

As the piston head moves into the cylinder in the operation of the device, the air compressed in the cylinder will tend to rush outthrough the ports 14s This tendency will cause the formation of a partial vacuum between the ports and the closure member, and this partial'vacuum and the rushof air against the outer face of'the closure; member will swing it about itspivots to closed position and the air pressure within the cylinder will maintain it closed during the latter part of the stroke. The valve will, however, open promptly upon reversal of movement of the piston, the air pressure from the outside through ports 14 and gravity acting upon the lower. portion 21 of the valve causing this opening movement.

The adjustment of the distance-of closing by means of the screw 22 will take care of varying conditions and requirements. It will be apparent, however, that the valves as made can be constructed with different characteristics by varying the angle between the upper' and lower portions, by varying the relative weights of the upper and lower portions and by varying the areas exposed to air pressure.

The form of packing shown upon the piston head is particularly efficient in constructions of'this type. The packing ring 25 is preferably formed of hard fibre although it diameter than the'cylinde'r. Upon being forced into thecylinder it consequently firmly engages the cylinder walls. The flexible packing 27 also engages the walls and serves to prevent passage, of air through minor clearances between the ring 25 andthe cylinder and through the split in the ring 25.

lVhile I have illustrated one form of my device, I contemplate suchchanges and modifications to adapt it to various condi-" tions of service as come within the scope of the appended claims.

Iclaim: I I

I '1. In; a fluid buffer, a cylinder and a solid piston head movable therein,a port in said piston head, a swinging valve pivoted to the solid piston head adjacent the port, said valve being normally maintained in open position and adapted to beclosed against the piston head to close the port therein, by fluid pressure in said cylinder. 1

2. In a fluid buffer, a cylinder and a piston headmovable therein,a swinging-valve pivoted adjacent said port, said valve being provided with a counterbalance, counterbalance serving bygravity to maintain the valve at one'limit of movement.

3. In a fluid buffer, a cylinder and a piston head movable therein, a port in said pis ton head movable therein, a portin said piston head, a swinging valve pivoted adjacent the port and adjustablemeans engaging the valve and adapted to limit its opening movement.

5. In a fluid buffer, a cylinder. and a piston head movable therein, a port in said. piston head, a swinging valve pivoted adjacent the port, said valve comprising a plate having two angularly related portions, one portion serving as a valve closure and the other as a counterbalance adapted to maintain the valve normally open.

6. In a fluid buffer, a cylinder and a piston head movable therein, a port in said piston head, a swinging valve pivoted adjacent the port, said valve comprising a plate have said ing two angularly related portions, one portion of the valve to limit the opening moveserving as a valve closure and the lower porment of the valve. tion of the plate being of a Weight adapted 10 7. In a fluid buffer, a cylinder and a pisnormally to swing the upper portion away ton head movable therein, a port extending from the face of the piston head to open the through the upper portion of the piston, a valve. valve comprising a plate bent upon a trans- Signed at Chicago, Illinois, this 13 day of verse line and supported by pivots upon the November, 1922. piston head, the upper portion of the plate GEORGE BOOTH. 

